Sensory modalities influence on hand perception


Previous research has found that the perception of one's hands is inaccurate. Furthermore, this inaccuracy has certain distinguishable patterns including an overestimation of hand width and an underestimation of finger length. The aim of the present study is to investigate the influence of vision to this distorted perception. Participants were required to place their hand underneath a glass tabletop and point to ten locations on their hand when their hand was visible (real condition) or hidden from view (perception condition). Participants had vision throughout the task (Group 1) or wore a blindfold during the perception portion of the task (Group 2). They completed the task by pointing with their own finger or with a wooden stylus, to investigate if proprioceptive feedback of the pointing hand influenced hand perception. The task was completed with both the right and left hands. Results replicated previous findings of an overestimation of hand width and underestimation of finger length, but participants were more accurate when vision was unavailable (Group 2). This finding suggests that vision interferes with hand representation. Proprioceptive feedback of the pointing hand played only a minor role with slightly more accurate representation when pointing with the finger. Finally, when compared to the left hand, right hand estimates were more distorted regardless of visual availability and pointer effector (finger or stylus).